JP2022139925A - Motor control system and motor controller - Google Patents

Abstract

To provide a technique to reduce a time lag from when a failure occurs until when all motors are stopped independent of a communication cycle between a motor controller and a host controller.SOLUTION: A motor control system comprises: a host controller that transmits operation command signals for controlling to drive motors to a plurality of motor controllers through a first communication line; and the plurality of motor controllers that control the drive of the motors based on the operation command signals. The motor controllers each include: a failure determination unit that, when a failure occurs in a predetermined circuit in the motor controller, determines as a first failure mode, when a failure occurs outside the predetermined circuit, determines as a second failure mode, and outputs failure mode information indicating the first failure mode or the second failure mode; a mode notification unit that notifies the failure mode information output from the failure determination unit to the other motor controllers through a second communication line; and a brake control unit that, when acquiring the failure mode information, stops the motor based on the failure mode information.SELECTED DRAWING: Figure 3

Description

The present invention relates to a motor control system and a motor control device that drive and control a motor.

In order to control the positioning of moving parts in a relatively large machine, there is known a motor control system that performs so-called tandem control, in which a plurality of servo motors cooperate to operate a single movable part (driven object). ing. Such a motor control system includes a plurality of servo motors that operate movable parts of various mechanical devices, a drive control device that drives and controls the plurality of servo motors, and a communication network for these drive control devices. There is a system provided with a host control device that centrally controls each drive control device by transmitting a command signal to the drive control device.

In Patent Document 1, while suppressing an increase in the number of signal lines included in a servo drive system in which one mechanism is driven by a plurality of servo motors, when a failure occurs in the servo drive system, those servo motors are turned off for a short time. A technique is disclosed to stop at and protect the mechanism from mechanical loads. Further, Patent Literature 2 discloses a device that continues servo control of a load even if an abnormality occurs in a constituent element of the servo control device.

JP-A-2003-169497 Japanese Patent Application Laid-Open No. 2001-202102

In a system in which a plurality of motors cooperate to drive one movable part, when one of the motors is stopped due to a failure, the other motors are also stopped together with the failed motor.
In this case, the drive control device that has detected the failure stops the motor it drives and controls, that is, the motor in which the failure has occurred, and notifies the host controller of the occurrence of the failure via the communication network. Then, the host control device notifies the other drive control devices of the occurrence of the failure via the communication network, and each drive control device stops the motors it is driving and controlling.
When a failure occurs in one of a plurality of motors cooperating in this way, it is desirable to stop all motors promptly, but it is also possible to prevent the occurrence of failures in other drive control devices via the host controller. In the notification method, it takes time to notify the upper control device of the failure and time for the upper control device to notify the other drive control devices of the failure. There was a problem that the time lag was large. Moreover, this time lag depends on the communication cycle of the communication network, and there is a problem that the time lag increases when the communication cycle is set large.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems. It is an object of the present invention to provide a technique for shortening the time lag from occurrence to stopping of all motors without depending on the communication cycle between a motor control device and a host control device.

In order to solve the above-described problems, a motor control system of the present invention is a system in which a host controller controls a plurality of motor control devices that drive and control a plurality of motors that drive the same driven object, wherein the host A control device transmits an operation command signal for driving and controlling the motor to the plurality of motor control devices via a first communication line, and each of the plurality of motor control devices transmits the operation command signal. a motor control unit for generating a command value designating the operation of the motor corresponding to the motor control device based on the signal; and a drive for driving the motor according to the command value from the motor control unit. A first failure mode is determined when a failure occurs in a drive unit that supplies current to the motor and a predetermined circuit in the motor control device itself, and a second failure mode is determined when a failure occurs in a circuit other than the predetermined circuit. a failure determination unit for determining a mode and outputting failure mode information indicating the first failure mode or the second failure mode; and the failure mode information output from the failure determination unit independent of the first communication line. a mode notification unit that notifies other motor control devices of the plurality of motor control devices other than the self motor control device via a second communication line that electrically connects the plurality of motor control devices; and a braking control unit for executing braking control for stopping the motor based on the acquired failure mode information regarding the self motor control device and the other motor control device.

As described above, the motor control system of the present invention, when a failure is detected in each motor control device, notifies the failure mode information to the other motor control devices without going through the host control device. The motor can be quickly stopped regardless of the communication cycle with the device. In addition, by stopping the motors driven and controlled by each motor control device by braking control selected based on failure mode information, each motor can be stopped appropriately by synchronizing the stop position and stop timing of each motor. can.

In order to solve the above-mentioned problems, a motor control device of the present invention is controlled by a host control device, and drives and controls a plurality of motors that drive the same driven object. A control device, which receives an operation command signal from the host control device via a first communication line, and based on the operation command signal, a command value specifying the operation of the motor corresponding to the motor control device. a driving unit for supplying a drive current for driving the motor to the motor according to the command value from the motor control unit; and a predetermined circuit in the motor control device itself. If a failure occurs in the above, it is determined as the first failure mode, and if a failure occurs in a circuit other than the predetermined circuit, it is determined as the second failure mode, and failure mode information indicating the first failure mode or the second failure mode is provided. a failure determination unit that outputs the failure mode information output from the failure determination unit via a second communication line that is independent of the first communication line and electrically connects the plurality of motor control devices; a mode notification unit for notifying other motor control devices other than the self motor control device among the plurality of motor control devices; a braking control unit that executes braking control for stopping the motor based on the mode information.

As described above, the motor control device of the present invention, when a failure is detected in each motor control device, notifies the failure mode information to the other motor control devices without going through the host control device. The motor can be quickly stopped regardless of the communication cycle with the device. In addition, by stopping the motors driven and controlled by each motor control device by braking control selected based on failure mode information, each motor can be stopped appropriately by synchronizing the stop position and stop timing of each motor. can.

When the failure mode information of the self motor control device indicates the first failure mode, the braking control section of the self motor control device controls to cut off the drive current supplied from the drive section to the motor. and the braking control unit of the other motor control device stops the motor corresponding to the other motor control device in synchronization with the speed of the motor corresponding to the self motor control device. may be executed.

When the failure mode information of the self motor control device indicates the second failure mode, the braking control unit of the self motor control device performs one of a plurality of braking controls for stopping the motor. The motor is stopped by the selected braking control, and the braking control unit of the other motor control device synchronizes with the motor corresponding to the self motor control device to stop the other motor control device. You may perform the control which stops the said motor corresponding to.

One of the plurality of braking controls is control for interrupting the drive current supplied from the drive section to the motor, wherein the braking control section of the self motor control device interrupts the drive current. is selected, the braking control unit of the other motor control device stops the motor corresponding to the other motor control device in synchronization with the speed of the motor corresponding to the self motor control device. control may be exercised.

When one of the plurality of braking controls is control for stopping the motor by dynamic braking, and the braking control unit of the self motor control device selects control for stopping the motor by the dynamic braking , the braking control unit of the other motor control device may execute control to stop the motor corresponding to the other motor control device in synchronization with the timing of the dynamic braking.

One of the plurality of braking controls is control to stop the motor by generating a torque for stopping the motor, wherein the braking control section of the self motor control device generates the torque. When the control to stop the motor is selected, the braking control unit of the other motor control device stops the motor corresponding to the other motor control device in synchronization with the torque generation timing. control may be exercised.

One of the plurality of braking controls is control for stopping the motor at a predetermined position, and the braking control unit of the self motor control device selects control for stopping the motor at a predetermined position. In this case, the braking control unit of the other motor control device stops the motor corresponding to the other motor control device at the predetermined position in synchronization with the motor corresponding to the self motor control device. control may be exercised.

One of the plurality of braking controls is control for stopping the motor at a predetermined deceleration, and the braking control unit of the self motor control device performs control for stopping the motor at the predetermined deceleration. When selected, the braking control unit of the other motor control device stops the motor corresponding to the other motor control device in synchronization with the speed of the motor corresponding to the self motor control device. may be executed.

The present invention relates to a system in which a plurality of motors cooperate to drive an object to be driven, and a host controller controls the drive control of the plurality of motors. can be shortened regardless of the communication cycle between the motor controller and the host controller.

1 is a schematic configuration diagram of a motor control system according to the present invention; FIG. 3 is a functional block diagram of a servo driver; FIG. It is a figure which shows the interruption|blocking process by a simultaneous stop control part at the time of abnormality.

FIG. 1 is a schematic configuration diagram of a motor control system 1 according to the present invention. The motor control system 1 includes a first network N1, a plurality of servo motors 2 (2A to 2C), a plurality of servo drivers 4 (4A to 4C), a PLC (Programmable Logic Controller) 5, and a second network N2. , and a driven object 60 . In this embodiment, reference numerals 4A to 4C are used when the plurality of servo drivers 4 (4A to 4C) are distinguished from each other, and reference numeral 4 is used when they are described without distinction. Similarly, the reference numerals 2A to 2C are used when the plurality of servo motors 2 (2A to 2C) are distinguished from each other, and the reference numeral 2 is used when they are described without distinction. In this embodiment, the servo driver 4 corresponds to a motor control device, and the PLC 5 corresponds to a host control device. The servomotor 2 of this embodiment includes a motor 21 and an encoder 22 .

The first network N1 is a first communication line to which a plurality of servo drivers 4 and PLCs 5 are connected and which enables mutual communication between the servo drivers 4 and the PLCs 5 . The first network N1 is, for example, Ether CAT. The second network N2 is a second communication line that electrically connects the plurality of servo drivers 4 independently of the first network. The second network N2 enables communication between the servo drivers 4 with each other.

In the motor control system 1, the PLC 5 sends an operation command signal via the first network N1 to a plurality of servo drivers 4 that drive and control the plurality of servo motors 2, respectively, so that the servo drivers 4 are collectively controlled. It is a system that controls and cooperates with a plurality of servo motors 2 to drive the same driven object 60 .

Each servo driver 4 monitors failures in its own predetermined circuit and other circuits than the predetermined circuit, such as the servo motor 2 driven and controlled by itself. is detected as the second failure mode. Then, the servo driver 4 that has detected the failure notifies the other servo drivers 4 of failure mode information indicating the first failure mode or the second failure mode via the second network N2, and based on the failure mode information , selects one of a plurality of braking controls for stopping the servomotor 2, and stops the servomotor 2 driven and controlled by itself according to the selected braking control.

Further, when each servo driver 4 receives failure mode information from another servo driver 4, it selects one of a plurality of braking controls based on this failure mode information, and according to the selected braking control, self Stop the servomotor 2 for drive control.

When each servo driver 4 detects a failure in this way, by notifying the other servo drivers 4 of the failure mode information without going through the PLC 5, the servo can be quickly operated without depending on the communication cycle between the servo driver 4 and the PLC 5. Motor 2 can be stopped. In addition, by stopping the servo motors 2 driven and controlled by the servo drivers 4 by braking control selected based on the failure mode information, the stop positions and stop timings of the servo motors 2 are aligned, and the servo motors 2 are appropriately controlled. can be stopped.

The servomotor 2 is incorporated in a mechanical device as an actuator of the mechanical device including the driven object 60 . The motor 21 of the servomotor 2 is, for example, an AC motor. An encoder 22 is then attached to the motor 21 to detect the operation of the motor 21 . The encoder 22 generates a feedback signal indicating the detected motion of the motor 21 and transmits the feedback signal to the servo driver 4 . The feedback signal includes, for example, position information about the rotational position (angle) of the rotating shaft of the motor 21, information about the rotating speed of the rotating shaft, and the like. A general incremental encoder or absolute encoder can be applied to the encoder 22 .

The driven object 60 is, for example, a mechanical device such as an arm of an industrial robot or a transport device. In the example of FIG. 1 , the driven object 60 has a moving stage 61 and a transmission mechanism 62 , and the moving stage 61 is connected to the motor 21 via the transmission mechanism 62 . The transmission mechanism 62 is a mechanism that transmits the driving force of the motor 21 to the moving stage 61, such as pulleys, drive belts, gears, and screw rods.

FIG. 2 is a functional block diagram of the servo driver 4. As shown in FIG. As shown in FIG. 2 , the servo driver 4 has a feedback processing section 41 , a motor control section 42 , a cutoff section 43 , a driving section 44 , and an abnormal simultaneous stop control section 50 . Feedback processing section 41 generates a feedback value based on the feedback signal from encoder 22 . For example, when pulses are output from the encoder 22, the feedback processing unit 41 calculates the position and moving speed of the motor 21 by counting the pulses, and generates a feedback value including values indicating the position and speed. .

The encoder 22 has a duplicated circuit so that independent pulses can be output by simultaneously scanning inside thereof, and duplicated feedback signals are output. Therefore, the feedback processing unit 41 receives duplicated feedback signals from the encoder 22 and generates duplicated feedback values based on those feedback signals. Then, the feedback processing unit 41 sends the generated duplicated feedback value to the motor control unit 42 and also to the simultaneous stop control unit 50 at the time of abnormality. The encoder 22 of the present embodiment is a safety encoder that outputs duplicated feedback signals, but is not limited to this, and may output non-duplicated feedback signals.

Next, the motor control section 42 receives an operation command signal from the PLC 5 and a feedback value from the feedback processing section 41 . The motor control unit 42 generates a command value for executing position feedback control and speed feedback control based on the operation command signal and the feedback value. For example, the motor control unit 42 causes the motor 21 connected to its own servo driver 4, in other words, the motor 21 corresponding to its own servo driver 4, to respond to the operation command signal by feedback control based on the operation command signal and the feedback value. A position command value and a speed command value are generated so as to follow. In addition, the feedback method adopted in the feedback control is a method in which a servo loop suitable for a predetermined purpose (for example, transporting a load) of a mechanical device (such as a transport device) in which the motor 21 is incorporated is formed. can be designed. These command values generated by the motor control unit 42 are sent to the cutoff unit 43 and the simultaneous stop control unit 50 in the event of an abnormality as drive signals.

Next, when receiving a cutoff signal from the abnormal simultaneous stop control unit 50, which will be described later, the cutoff unit 43 electrically prevents the drive signal from the motor control unit 42 from passing through the drive unit 44, which will be described later. Stop unit 44 . As a result, the motor 21 is stopped even if the motor control unit 42 sends out the drive signal. On the other hand, when the shutoff signal is not input to the shutoff unit 43, the shutoff unit 43 passes the driving signal accompanied by the command value output from the motor control unit 42 to the driving unit 44 as it is. It should be noted that the blocking unit 43 is not limited to a configuration that exists independently of the functional units such as the motor control unit 42. The drive unit 44 may be stopped by stopping the output of the position command value and the speed command value when the signal is received.

The drive section 44 receives a drive signal from the motor control section 42 via the cutoff section 43 . The driving unit 44 has a circuit composed of a semiconductor switching element such as an IGBT (Insulated Gate Bipolar Transistor), for example. A signal for turning off is generated, and the switching element is turned on/off according to the signal. AC power is thereby supplied to the motor 21, and the motor 21 is driven according to the drive signal. On the other hand, when the cutoff portion 43 operates to cut off the transmission of the drive signal to the drive portion 44, the output from the drive portion 44 is fixed to be off. Since the power supply to the motor 21 is thereby stopped, torque output from the motor 21 is stopped.

The dynamic braking unit 45 includes a resistor 451 and a relay 452, and closes the relay 452 in response to a command from the simultaneous stop control unit 50 at the time of braking the motor 21 as will be described later. By consuming the kinetic energy in the resistor 451, the kinetic energy of the motor 21 is eliminated and stopped.

Thus, the feedback processing unit 41, the motor control unit 42, the cutoff unit 43, and the driving unit 44 are functional units directly related to the drive control of the motor 21, so to speak. On the other hand, the abnormal simultaneous stop control unit 50 determines the occurrence of a failure in the operation of the encoder 22, and if it is determined that a failure has occurred, stops the operation of the motor 21 to ensure the safety of the operation. It is a function part to secure. More specifically, the simultaneous stop control unit 50 at abnormal time has a failure determination unit 51 , a mode notification unit 52 and a braking control unit 53 .

The failure determination unit 51 detects a failure based on the operation command signal received from the PLC 5, the feedback value received from the feedback processing unit 41, the command value received from the motor control unit 42, and the feedback signal received from the encoder 22. For example, the failure determination unit 51 receives duplicated feedback signals from the encoder, compares them, detects that there is no failure if there is no difference equal to or greater than the threshold, that is, that it is normal, and If there is a difference between , it is detected that the servomotor 2 has failed.

Further, the failure determination unit 51 receives duplicated feedback values from the feedback processing unit 41, compares them, and detects that no failure has occurred, that is, that the system is normal if there is no difference equal to or greater than a threshold value. , and the feedback signal from the encoder 22 is normal, it is detected that the feedback processing unit 41 has failed. Further, the failure determination unit 51 estimates the command value output by the motor control unit based on the feedback value received from the feedback processing unit 41 and the operation command value received from the PLC 5, and the estimated command value and the motor control unit 42, and if there is no difference equal to or greater than the threshold, it is detected that no failure has occurred, that is, that the motor control unit 42 is normal. Detect what happened.

Furthermore, the simultaneous stop control unit 50 is duplicated, and the failure determination unit 51 compares the mutual outputs, and if there is no difference equal to or greater than the threshold value, it detects that no failure has occurred, that is, that it is normal. If there is the above difference, it is detected that the simultaneous stop control unit 50 has failed. In this embodiment, the feedback processing unit 41, the motor control unit 42, and the simultaneous stop control unit 50 are predetermined circuits (main circuits), and the failure determination unit 51 detects that a failure has occurred in these predetermined circuits. is determined to be the first failure mode. Further, the failure determination unit 51 determines that the failure mode is the second failure mode when it detects that a failure has occurred in a circuit other than the predetermined circuit, for example, the servomotor 2 . Then, when detecting that a failure has occurred, the failure determination unit 51 outputs failure mode information indicating the first failure mode or the second failure mode. These failure judgments are not limited to comparison of duplicated signals, and failure judgments are made by other methods such as comparison with command values, etc., and whether the signal value deviates from the normal range. It's okay.

When the failure determination unit 51 detects that a failure has occurred, the mode notification unit 52 transmits failure mode information output from the failure determination unit 51 via the second network N2 different from the first network N1. The other servo drivers 4 other than the self servo driver 4 among the plurality of servo drivers 4 are notified.

When the braking control unit 53 acquires failure mode information from another servo driver 4 or acquires failure mode information from the failure determination unit 51 belonging to the same simultaneous stop control unit 50, the braking control unit 53 uses the acquired failure mode information. Braking control for stopping the motor 21 is performed based on. Here, the braking control includes, for example, braking by free run (first braking control), braking by dynamic braking (second braking control), braking by stopping torque (third braking control), braking at a predetermined position ( fourth braking control), control at a predetermined deceleration (fifth braking control), and the like.

Braking by free-running (first braking control) is control to stop the motor by sending a cutoff signal to the cutoff unit 43 and operating the cutoff unit to cut off the drive current supplied to the motor 21 . In this case, after the drive current is cut off, the motor 21 moves slightly due to inertia, but stops when the drive torque is no longer generated.

Braking by the dynamic brake (second braking control) sets the command value by the motor control unit 42 to 0 rpm or operates the cutoff unit 43 to cut off the drive current to brake the motor 21, and the dynamic brake unit 45 is commanded is sent to close the relay 452, the regenerated current from the motor 21 is consumed by the resistor 451, and the motor 21 is quickly stopped.

Braking by stopping torque (third braking control) is control for sending a command signal to the motor control unit 42 and outputting a driving signal so as to generate stopping torque.

Braking at a predetermined position (fourth braking control) is control in which a command signal is sent to the motor control unit 42 and a drive signal is output so as to stop the motor at a position after moving a predetermined distance from the time when the failure occurred. If this position can be specified by the elapsed time from the time when the failure occurred or by the step, the position that exists after the time when the failure occurred, or the position after a predetermined number of steps after the time when the failure occurred. may

Control at a predetermined deceleration (fifth braking control) sends a command signal to the motor control unit 42 to output a drive signal so that the motor 21 is decelerated at a predetermined deceleration from the time when the failure occurs until the motor 21 stops. Control.

The user sets in advance which braking control is selected according to the failure mode information. For example, when a failure occurs in a predetermined circuit of the servo driver 4, that is, the braking control unit 53 acquires failure mode information indicating the first failure mode from the failure determination unit 51 belonging to the same simultaneous stop control unit 50. In this case, the servo driver 4 is set so that the first braking control is selected because there is a possibility that the motor 21 cannot be controlled appropriately. Braking control when the braking control unit 53 acquires the failure mode information indicating the second failure mode from the failure determination unit 51 belonging to the same simultaneous stop control unit 50 can be arbitrarily performed according to the specifications of the driven object 60. may be set. For example, any one of the second to fifth braking controls is set. The braking control setting selected by the servo driver 4 in which the failure has occurred or the servo driver 4 that drives and controls the motor 21 in which the failure has occurred is also referred to as failure time setting. When a failure occurs in the servo driver 4 or the motor 21 corresponding to the servo driver 4, the servo driver 4 and the motor 21 are referred to as the failed servo driver 4 and the failed motor 21, respectively. The other servo driver 4 and motor 21 that are not connected are referred to as the normal side servo driver 4 and the normal side motor 21 .

The servo driver 4 on the normal side, that is, the servo driver 4 whose braking control unit 53 has acquired failure mode information from another servo driver 4, drives itself in synchronization with the motor 21 controlled by the failure side servo driver 4. The motor 21 to be controlled is stopped. For example, if the time lag between when the normal servo driver 4 is notified of the failure mode information after the failure occurs and when the braking control is executed is negligibly small, the normal servo driver 4 and the failure servo driver 4 The same braking control may be selected.

For example, when a failure occurs in a predetermined circuit of the servo driver 4A, the servo driver 4A determines that it is in the first failure mode, selects the first braking control, and stops the motor 21 by coasting, another servo driver 4B and 4C also select the first braking control and stop the motor 21 in free run, thereby stopping the motor 21 in synchronization with the speed of the motor 21 on the failure side. Further, when a failure occurs in the servomotor 2A and the servo driver 4A determines that it is in the second failure mode, when one of the second to fifth braking modes is selected according to the failure setting to stop the motor 21, The other servo drivers 4B and 4C also select the same braking control to stop the motor 21.

Further, if there is a predetermined time lag between when the normal servo driver 4 is notified of the failure mode information after the failure occurs and when the braking control is executed, the normal servo driver 4 takes this time lag into account and selects the failure mode information. Braking control may be performed so as to stop the servo motor 2 controlled by the servo driver 4 in synchronization with the servo motor 2 controlled by the servo driver 4 . For example, when the stop position of the motor 21 on the normal side is delayed by one step compared to the motor 21 on the failure side, the servo driver 4A on the failure side selects the first braking control and free-runs a predetermined step ( When the servo motor 2A is expected to stop after 3 steps in this example), the normal side servo drivers 4B and 4C select the fourth braking control, and take a predetermined step (3 steps in this example) after receiving the failure mode information. ), that is, four steps after the occurrence of the failure, the servomotors 2B and 2C are stopped. As a result, the failed servo motor 2A and the normal servo motors 2B and 2C can be stopped in the same positional relationship.

Further, the normal servo drivers 4B and 4C stop the normal servo motors 2B and 2C in synchronization with the malfunction servo motor 2A according to the braking control executed by the malfunction servo driver 4A. For example, when the failure-side servo driver 4A selects control (second braking control) to stop the failure-side servomotor 2A by dynamic braking, the braking control units 53 of the normal-side servo drivers 4B and 4C control the timing of the dynamic braking. , the normal side servomotors 2B and 2C are stopped. Similarly, when the faulty servo driver 4A selects control (third braking control) for generating torque to stop the faulty servomotor 2A, the braking control units 53 of the normal servo drivers 4B and 4C The normal side servomotors 2B and 2C are stopped in synchronization with the torque generation timing. When the malfunctioning servo driver 4A selects the control (fourth braking control) to stop the malfunctioning servomotor 2A at a predetermined position, the braking control units 53 of the normal servo drivers 4B and 4C control the malfunctioning servomotor 2A. , the normal side servomotors 2B and 2C are stopped at the predetermined position. Further, when the faulty servo driver 4A selects the control (fifth braking control) to stop the faulty servomotor 2A at a predetermined deceleration, the braking control units 53 of the normal servo drivers 4B and 4C The normal side servomotors 2B and 2C are stopped in synchronization with the deceleration of the servomotor 2A.

Here, the braking control by the simultaneous stop control section 50 having the failure determination section 51 and the braking control section 53 will be described with reference to FIG. The braking control shown in FIG. 3 is repeatedly executed, for example, at a control cycle in which a command value is generated by an arithmetic unit (such as an MPU) that forms the simultaneous stop control unit 50 in the event of an abnormality. In step S<b>101 , the failure determination unit 51 acquires an operation command signal from the PLC 5 , a feedback value from the feedback processing unit 41 , a command value from the motor control unit 42 , and a feedback signal from the encoder 22 .

In step S102, the failure determination unit 51 performs processing for determining whether or not a failure has occurred based on the operation command signal, feedback value, command value, and feedback signal acquired in step S101. For determination of a failure, for example, these duplicated signals are compared, and if there is a difference of a threshold value or more, it is determined that a failure has occurred. These failure judgments are not limited to comparison of duplicated signals, and failure judgments are made by other methods such as comparison with command values, etc., and whether the signal value deviates from the normal range. It's okay.

In the case of an affirmative determination in step S102, the failure determination unit 51 proceeds to step S103 and determines whether the failure mode is the first failure mode according to the failure location. In the case of an affirmative determination in step S103, the failure determination unit 51 proceeds to step S104 and selects the first braking control according to the failure setting. Then, in step S105, the braking control section 53 stops the servomotor 2 according to the first braking control.

On the other hand, if the determination in step S103 is negative, the failure determination unit 51 proceeds to step S106 and selects any one of the second to fifth braking controls according to the failure setting. Then, in step S107, the braking control unit 53 stops the servomotor 2 according to the braking control selected in step S106.

If the determination in step S102 is negative, the failure determination section 51 proceeds to step S108 and determines whether failure mode information has been received from another servo driver 4 or not. If the determination in step S108 is negative, the failure determination unit 51 ends the processing of FIG. Let

As described above, according to the present embodiment, when a failure is detected in the servo driver 4, the communication cycle between the servo driver 4 and the PLC 5 is shortened by notifying the failure mode information to the other servo drivers 4 without going through the PLC 5. Therefore, the servomotor 2 can be quickly stopped. In addition, the normal side servo driver 4 synchronizes the servo motors 2 with the failure side servo motors 2 and performs braking control, so that the stop positions and stop timings of the servo motors 2 are aligned and the respective servo motors 2 are stopped appropriately. can be made

1: Motor control system 2 (2A to 2C): Servo motor 4 (4A to 4C): Servo driver 21: Motor 22: Encoder 41: Feedback processing unit 42: Motor control unit 43: Cutoff unit 44: Driving unit 45: Dynamic Brake unit 50 : Simultaneous stop control unit 51 : Failure determination unit 52 : Mode notification unit 53 : Braking control unit 60 : Driven object 61 : Moving stage 62 : Transmission mechanism 451 : Resistor 452 : Relay N1 : First network N2 : Second network

Claims (9)

A motor control system in which a host control device controls a plurality of motor control devices that respectively drive and control a plurality of motors that drive the same driven object,
The host control device transmits an operation command signal for driving and controlling the motors to the plurality of motor control devices via a first communication line,
each of the plurality of motor controllers,
a motor control unit that generates a command value designating the operation of the motor corresponding to the motor control device based on the operation command signal;
a drive unit that supplies a drive current for driving the motor to the motor according to the command value from the motor control unit;
When a failure occurs in a predetermined circuit in the motor control device of itself, it is determined as a first failure mode, and when a failure occurs in a circuit other than the predetermined circuit, it is determined as a second failure mode, and the first failure mode or a failure determination unit that outputs failure mode information indicating a second failure mode;
The failure mode information output from the failure determination unit is transmitted to the plurality of motor control devices via a second communication line that is independent of the first communication line and electrically connects the plurality of motor control devices. a mode notification unit that notifies other motor control devices other than the self motor control device;
a braking control unit that executes braking control for stopping the motor based on the acquired failure mode information regarding the self motor control device and the other motor control device;
A motor control system, comprising: When the failure mode information of the self motor control device indicates the first failure mode,
The braking control unit of the self motor control device executes control to cut off the drive current supplied from the drive unit to the motor,
The braking control unit of the other motor control device executes control to stop the motor corresponding to the other motor control device in synchronization with the speed of the motor corresponding to the self motor control device.
The motor control system of claim 1. When the failure mode information of the self motor control device indicates the second failure mode,
The braking control unit of the self motor control device selects one of a plurality of braking controls for stopping the motor, and stops the motor with the selected braking control,
The braking control unit of the other motor control device executes control to stop the motor corresponding to the other motor control device in synchronization with the motor corresponding to the self motor control device.
The motor control system of claim 1. one of the plurality of braking controls is control for interrupting the drive current supplied from the drive unit to the motor,
When the braking control unit of the self motor control device selects control to cut off the drive current, the braking control unit of the other motor control device controls the motor corresponding to the self motor control device. executing control to stop the motor corresponding to the other motor control device in synchronization with the speed;
4. A motor control system according to claim 3. one of the plurality of braking controls is control for stopping the motor by dynamic braking,
When the braking control unit of the self motor control device selects control to stop the motor by the dynamic brake, the braking control unit of the other motor control device synchronizes with the timing of the dynamic brake. , executing control to stop the motor corresponding to the other motor control device;
4. A motor control system according to claim 3. one of the plurality of braking controls is control for generating a torque for stopping the motor to stop the motor,
When the braking control unit of the self motor control device selects control to generate the torque and stop the motor, the braking control unit of the other motor control device synchronizes with the torque generation timing. and execute control to stop the motor corresponding to the other motor control device;
4. A motor control system according to claim 3. one of the plurality of braking controls is control for stopping the motor at a predetermined position,
When the braking control unit of the self motor control device selects control to stop the motor at a predetermined position, the braking control unit of the other motor control device corresponds to the self motor control device. executing control to stop the motor corresponding to the other motor control device at the predetermined position in synchronization with the motor;
The motor control system according to any one of claims 1 to 4. One of the plurality of braking controls is control for stopping the motor at a predetermined deceleration,
When the braking control unit of the self motor control device selects control to stop the motor at a predetermined deceleration, the braking control unit of the other motor control device corresponds to the self motor control device. executing control to stop the motor corresponding to the other motor control device in synchronization with the speed of the motor that
The motor control system according to any one of claims 1 to 5. One motor control device among a plurality of motor control devices that are controlled by a host control device and that respectively drive and control a plurality of motors that drive the same driven object,
A motor control unit that receives an operation command signal from the host control device via a first communication line and generates a command value designating the operation of the motor corresponding to the motor control device based on the operation command signal. When,
a drive unit that supplies a drive current for driving the motor to the motor according to the command value from the motor control unit;
When a failure occurs in a predetermined circuit in the motor control device of itself, it is determined as a first failure mode, and when a failure occurs in a circuit other than the predetermined circuit, it is determined as a second failure mode, and the first failure mode or a failure determination unit that outputs failure mode information indicating a second failure mode;
The failure mode information output from the failure determination unit is transmitted to the plurality of motor control devices via a second communication line that is independent of the first communication line and electrically connects the plurality of motor control devices. a mode notification unit that notifies other motor control devices other than the self motor control device;
a braking control unit that executes braking control for stopping the motor based on the acquired failure mode information regarding the self motor control device and the other motor control device;
A motor controller comprising:

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